This is my first HTC device and the stock Rom nandroid for my Cid isn't twrp compatible and cwm is doing what I already it to do. That's problem one, I have never seen such messy system to return to stock, CIDs and all this rubbish. And I swear for all these years I've never had to flash a firmware in order to flash a Rom, and heck, even pay to have full rights over my device (sunshine) I'd say HTC is the least friendly phone I've used by far when it comes to flashing custom roms
HTC is reasonably good in this regard, IMO, having dealt with some 30 phones over 3 years for testing my apps.
HTC has bootloader unlock program. LG has nothing like that (Although allegedly considering it). I hate my G2 for that reason.
I've never directly dealt with Samsungs' KNOX, but that creates major headaches too.
We are lucky to have ANY S-Off solution.
We are also lucky to have so much enthusiast & ROM dev interest in the M8. Some of the forums here on XDA are barren.